Since its inception in the 1970s the commercial semiconductor industry has experienced continuous, unprecedented growth. As the industry keeps expanding exponentially, fueled by the demand for faster, smaller, and more complex electronic devices, the challenges abound for chemical engineers.
Greater and greater performance requirements mean more and more sophisticated semiconductor chips. And at the same time manufacturing and environmental concerns must be addressed.
In 1965 Gordon Moore, a cofounder of Intel Corporation, predicted that the number of transistors able to be placed on a chip would double approximately every 18 months. Now known as Moore’s law, his prediction still holds true today.
In an article titled “Cramming More Components onto Integrated Circuits,” which was published in April 1965, Gordon Moore predicted that the number of transistors able to be put on a microchip would double approximately every 18 months. Still accurate today, this prediction is widely known as Moore’s law.
Moore’s law has held true ever since the early 1970s. Computer functionality has become faster and faster, and computerized devices can carry out more operations of greater and greater complexity.
Chemistry meets electronic engineering
Gordon Moore, a cofounder of Intel Corporation, is considered one of the first of a new breed of electronics engineers, primarily because his background was in chemistry. The first hire of the company - and one whose contributions qualify him as a founder - was Andrew Grove, a chemical engineer who went on to lead the company in the 1980s and 1990s.
As performance demands on today’s sophisticated semiconductor chips continue to grow, so does the need to manufacture larger quantities of chips with greater precision and smaller dimensions. This need requires chemical-engineering expertise to help make breakthroughs at the nanoscale.
Water use and reuse
Sustainable manufacturing is concerned with the application of innovative engineering strategies in order to maximize recycling of ultrapure chemicals, gases, and, in particular, water. The main objective is to reduce the volume and the toxicity of the waste streams.
Clean, green, and sustainable
The relatively new industrial focus on sustainable, or clean, manufacturing aims to maximize the reuse and recycling of natural resources. Water is a major raw material consumed during the manufacture of chips. Much of it is highly purified and used only once. Semiconductor manufacturers are now investigating methods of reducing the amount of water used per square inch when making silicon chips.
Advanced rinsing techniques that reduce water consumption are being developed and incorporated into the chip-making process. New purification technologies are being created to treat used water and remove impurities. The rigorous cleanliness standards required in each step of the chip-making process allow the water to be recycled and reused rather than simply being discharged from the process.
Advanced chip making
Most current semiconductor manufacturing processes are subtractive, where excess materials are removed by etching. The newer, less wasteful additive process involves metal or silicon being placed only where needed.
Currently, the traditional method of semiconductor manufacture is a subtractive process. That is, successive layers of metal are first deposited on the wafer surface to create the multilayer electronic circuitry. With the patterning of each new surface the unwanted materials are removed by etching.
Only a small amount of the raw materials used in the process actually ends up in the final product. Chemical engineers have focused on reducing the waste by developing innovative ways to increase the recycling and reuse of raw materials.
Newer additive processes that require fewer steps are also being designed. Manufacturers can selectively place metal, silicon, or other materials on the chip surface just where they are needed to create the desired circuitry. This method not only decreases the amount of materials required but also the amount of waste material produced during manufacturing.